A conventional backhoe comprises a boom section which attaches to the back of a tractor or other support structure and supports a dipper section. The dipper section is hingedly connected to the boom section so as to be tiltable about an axis transverse to the boom section. Tilting is generally achieved through the use of a fluid cylinder, referred to as a "crowd" cylinder extending between the dipper section and the boom section of the backhoe.
A tool is generally mounted to the dipper section at the end opposite that which attaches to the boom section. The particular tool will depend on the application to which the backhoe is being put. The tool may be a bucket when the backhoe is used for digging. Alternatively the tool may be a pneumatic drilling or chiselling device for use in descaling furnace walls or the like.
While in some applications simply rotating the dipper section about the pivotal connection to the boom section provides adequate control of the tool, in certain applications it is desirable to be able to tilt the dipper section relative to the boom section about a further axis which may, for example, be orthogonal to the first axis.
Previously the tilting of the dipper section about the first axis has been achieved by providing a boom which is rotatable about an axis extending along its length. A disadvantage to such boom structures is their tendency to break, the amount of maintenance required and the limited amount of tilting force which such booms may exert. Another disadvantage with such devices is that a special boom is required in order to enable the dipper to rotate.
It is therefore an object of this invention to provide a device for attaching a dipper section of a backhoe to a conventional boom section while permitting the two sections to pivot relative to each other about two non-parallel axes. Further objects of this invention include providing such an attachment device which is of relatively simple and robust construction to provide good tilting force ("swing pressure") and require minimal maintenance.
Other features and advantages of the invention will be become apparent upon reviewing the description which follows.